Micrometer head



March 3l, 1949- C. F. GOODSPEED MICROMETER HEAD Filed April 3, 1945 I n z/en to r Patented Mar. 1, 1949 MICROMETER HEAD Charles F. Goodspeed, Norwood, R. I., assignor of fifty per cent to Chester E. Wilbur, Oakland Beach, R. I.

Application April 3, 1945, Serial No. 586,304

1 Claim.

This invention relates to a micrometer head. A primary object of the invention is the provision of a device adapted to be utilized in conjunction with a micrometer for measuring the degree of pressure applied to the micrometer screw, thus eliminating the element of feel or touch between two or more persons taking micrometer measurements on the same parts, such, for example, as a machine operator and an inspector.

An additional object of the invention is the provision of a device designed to eliminate the human element from micrometer measurements, thereby making measurements in ten thousandths of an inch practical and accurate to within the accuracy of the individual micrometer itself.

An additional object of the invention is the provision of an improved measurement device, characterized by extreme sensitivity, and so designed as to preclude minute diiferences in ne measurements.

Still another object is the provision of such a device which will be sturdy and durable in construction, exceptionally accurate and reliable in operation, and relatively simple and inexpensive to manufacture and assemble.

Further objects reside in the combinations of elements, arrangements of parts, and features of construction, all as will b e more fully pointed out hereinafter and disclosed in the accompanying drawing where there is shown a preferred embodiment of this inventive concept.

In the drawings:

Figure 1 is a side elevational view, partially broken away, showing one form of head in accordance with this inventive concept,

Figure 2 is a longitudinal sectional view taken substantially through the center line of the device in Figure 1,

Figure 3 is an exploded plan View of certain constructional elements,

Figure 4 is a plan View of a constructional detail, and

Figure 5 is a sectional view taken substantially along the line 5-5 of Figure 2.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Having reference now to the drawing, it will be seen that the device is comprised of a micrometer spindle I0, to which is secured a head cap II, as by means of a screw I2. A micrometer thimble I3 surrounds the spindle I0, and has a head I4 in turn positioned thereabout. A counterhead I5 is also provided adjacent the juncture of the head and the thimble, and provided with the customary graduations IB.

Positioned in a suitable recess under the head cap II is a tension spring Il, one end of which is secured to an anchor pin I8, carried by the head.

The head I4 is provided with an internal flange 26, adjacent its upper extremity, in which flange is an elongated slotl 2 I, into which extends a stop pin 22, secured to the upper portion of thimble I3.

From the foregoing the operation of the device should now be readily understandable. Head Ill is free to turn clockwise on thimble I3, as is the counterhead I5, to within the limits of the elongated slot 2I, but is under counterclockwse tension of spring I7. In the operation, the head i4 is turned counterclockwise until the graduations on counterhead I5 are aligned with the graduations as desired on thimble I3, after which a reading may be taken in the usual manner. Thus, it will be seen that the spring I1 compensates for any variations in the individuals touch or feel.

Means are provided for varying the spring tension of the spring I1, which means comprise loosening the screw I2 and turning the head cap II in either direction until the desired tension is produced. Screw I2 may then be re-tightened, and the micrometer reset to the new tension.

From the foregoing, it will now be seen that there is herein provided a device accomplishing all of the objects of this invention, and others, including many advantages of great practical utility and commercial importance.

As many embodiments may be made of this inventive concept, and as many modifications may be made in the embodient hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense.

I claim:

In a device of the character described, aspindle, a thimble thereon, a head surrounding said thimble, an internal flange on said head having a slot therein, a pin on said thimble extending into said slot for limiting relative rotation between said ilange and said thimble, and spring means rotationally biasing said thimble and said head, whereby said head is turned against the biasing resistance of the spring until the force of resistance set up by the said spindle which is anchored to said spring, is overcome.

CHARLES F. GOODSPE-ED.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 346,456 Barnes Aug. 3, 1886 902,492 Jaques Oct. 27, 1908 2,267,332 Hagstrom Dec. 23, 1941 

